Several types of liquid smoke products are known in the food processing industry. One well-known type is an aqueous smoke solution which is produced in accordance with the method of Hollenbeck U.S. Pat. No. 3,106,473. Such an aqueous smoke solution is relatively light in smoke flavor, and is usable only in the processing of foods with which water is compatible. Hollenbeck U.S. Pat. No. 3,480,446 discloses a method of preparing a smoke flavored edible oil. A smoke flavored oil produced by the method of patent 3,480,446 also has a rather light smoke flavor, because its starting material is the aqueous smoke flavored solution of patent 3,106,473.
When wood smoke is extracted in water, or in the presence of water, there is a substantial heavy fraction of essentially water insoluble material. That material is herein referred to as "wood tar", and the term "wood tar" will be used throughout this specification and claims as the name for that material, which is a very complex mixture of organic compounds. It has heretofore been considered to be a waste product, and is one which presents a severe disposal problem.